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DShotRMT - ESP32 Library (Rewrite for ESP-IDF 5)

A modern, robust C++ library for generating DShot signals on the ESP32 using the new ESP-IDF 5 RMT encoder API (rmt_tx.h / rmt_rx.h).
Supports all standard DShot modes (150, 300, 600, 1200) and features continuous frame transmission with configurable timing.
Now with BiDirectional DShot support and advanced command management!

The legacy version (using the old rmt.h API) is still available in the oldAPI branch.

🚀 Features

All DShot Modes: DSHOT150, DSHOT300 (default), DSHOT600, DSHOT1200
BiDirectional DShot: Full support for RPM telemetry feedback
Advanced Command Manager: High-level API for ESC configuration and control
Command Sequences: Predefined initialization and calibration sequences
Hardware-Timed Signals: Independent, precise signal generation using ESP32 RMT peripheral
Configurable Timing: Ensures ESCs can reliably detect frame boundaries
Error Handling: Comprehensive result reporting with success/failure status
Simple API: Easy integration into your Arduino or ESP-IDF project

📦 Installation

Arduino IDE

Search "Arduino Library Manager" for "DShotRMT"

Clone this repository or download as ZIP
Place in your Arduino libraries folder (~/Arduino/libraries/DShotRMT/)
Restart Arduino IDE

PlatformIO

Add to your platformio.ini:

lib_deps = 
    https://github.com/derdoktor667/DShotRMT.git

Manual Installation

git clone https://github.com/derdoktor667/DShotRMT.git

⚡ Quick Start

Basic Usage (DShotRMT)

#include <DShotRMT.h>

// Create motor instance (GPIO 17, DSHOT300, non-bidirectional)
DShotRMT motor(17, DSHOT300, false);

void setup() {
    Serial.begin(115200);
    
    // Initialize the motor
    dshot_result_t result = motor.begin();
    if (result.success) {
        Serial.println("Motor initialized successfully");
    } else {
        Serial.printf("Motor init failed: %s\n", result.msg);
    }
}

void loop() {
    // Send throttle value (48-2047)
    dshot_result_t result = motor.sendThrottle(1000);
    if (!result.success) {
        Serial.printf("Throttle command failed: %s\n", result.msg);
    }
}

Bidirectional DShot (RPM Telemetry)

#include <DShotRMT.h>

// Enable bidirectional mode for telemetry
DShotRMT motor(17, DSHOT300, true);

void setup() {
    Serial.begin(115200);
    motor.begin();
}

void loop() {
    // Send throttle
    motor.sendThrottle(1000);
    
    // Get telemetry data
    dshot_telemetry_result_t telemetry = motor.getTelemetry(14); // 14 magnets
    if (telemetry.success) {
        Serial.printf("eRPM: %u, Motor RPM: %u\n", 
          telemetry.erpm, 
          telemetry.motor_rpm);
    }
}

📚 Examples

The library includes comprehensive examples:

1. Basic DShot Control (`dshot300.ino`)

Simple throttle control
Command execution
Serial interface for testing
Telemetry reading (if bidirectional enabled)

2. Advanced Command Management (`command_manager.ino`)

Interactive ESC control with full menu system:

=== DShot Command Manager Menu ===
 1 - Stop Motor
 2 - Activate Beacon 1
 3 - Set Normal Spin Direction
 4 - Set Reversed Spin Direction
 5 - Get ESC Info
 6 - Turn LED 0 ON
 7 - Turn LED 0 OFF
 0 - Emergency Stop

Advanced Commands:
 cmd <number>       - Send DShot command (0-47)
 throttle <value>   - Set throttle (48-2047)
 repeat cmd <num> count <count> - Repeat command

🔧 Hardware Configuration

Supported DShot Modes

Mode	Bitrate	Bit Time	Frame Time	Use Case
DSHOT150	150 kbit/s	6.67 µs	~107 µs	Long wires, EMI-prone
DSHOT300	300 kbit/s	3.33 µs	~53 µs	Standard (recommended)
DSHOT600	600 kbit/s	1.67 µs	~27 µs	High performance
DSHOT1200	1200 kbit/s	0.83 µs	~13 µs	Racing applications

GPIO Configuration

// Using GPIO number
DShotRMT motor(17, DSHOT300);

// Using GPIO enum
DShotRMT motor(GPIO_NUM_17, DSHOT300);

// With bidirectional support
DShotRMT motor(17, DSHOT300, true);

🎯 DShot Commands

Command	Value	Description	Usage
MOTOR_STOP	0	Stop motor	Always available
BEACON1 - 5	1 - 5	Motor beeping	Motor identification
ESC_INFO	6	Request ESC info	Get ESC version/settings
SPIN_DIRECTION_1/2	7 - 8	Set spin direction	Motor configuration
3D_MODE_OFF/ON	9 - 10	3D mode control	Bidirectional flight
SAVE_SETTINGS	12	Save to EEPROM	Permanent configuration
EXTENDED_TELEMETRY_ENABLE/DISABLE	13 - 14	Telemetry control	Data transmission
SPIN_DIRECTION_NORMAL/REVERSED	20 - 21	Spin direction	Alias commands
LED0-3_ON/OFF	22 - 29	LED control	BLHeli32 only
AUDIO_STREAM_MODE	30	Audio mode toggle	KISS ESCs
SILENT_MODE	31	Silent mode toggle	KISS ESCs

📚 DShot Protocol Details

Packet Structure

Each DShot frame consists of 16 bits:

11 bits: Throttle/command value (0-2047)
1 bit: Telemetry request flag
4 bits: CRC checksum

Checksum Calculation

// Standard DShot CRC
uint16_t crc = (data ^ (data >> 4) ^ (data >> 8)) & 0x0F;

// Bidirectional DShot (inverted CRC)
uint16_t crc = (~(data ^ (data >> 4) ^ (data >> 8))) & 0x0F;

Bidirectional DShot

Inverted Logic: High/low levels are inverted
GCR Encoding: Telemetry uses Group Code Recording
21-bit Response: 1 start + 16 data + 4 CRC bits
eRPM Data: Electrical RPM transmitted back to controller

🛠️ ESP32 RMT Peripheral

The library utilizes the ESP32's RMT (Remote Control) peripheral for precise signal generation:

Advantages

Hardware Timing: No CPU intervention during transmission
Concurrent Operation: Multiple channels can run simultaneously
DMA Support: Efficient memory-to-peripheral transfers

📖 References & Documentation

DShot Protocol

ESP32 Documentation

🤝 Contributing

We welcome contributions! Please:

Fork the repository
Create a feature branch
Make your changes with tests
Submit a pull request

Development Guidelines

Follow existing code style
Add documentation for new features
Include examples where appropriate
Test with real hardware when possible

Reporting Issues

When reporting issues, please include:

ESP32 board type and version
Arduino/ESP-IDF version
ESC type and firmware
Complete error messages
Minimal reproduction code

📄 License

MIT License – see LICENSE

👤 Author

Wastl Kraus

GitHub: @derdoktor667
Website: wir-sind-die-matrix.de

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